Method of operating catalytic ignition cyclic engines

Abstract

Disclosed is a method of operating a catalytic ignition internal combustion engine wherein the fuel is injected into a combustion chamber at a time near maximum compression such that at least part of the fuel impinges upon an oxidation catalyst surface comprising a portion of the wall of said combustion chamber, said catalytic surface being insulated from the surroundings external to the combustion chamber by a low thermal conductivity material, said catalytic surface preferably comprising platinum. Also disclosed are combustion chambers constructed specially for the use of this method and the methods of constructing them.

I claim: 
     
       1. A piston for use in compression ignition engines which comprises a crown, an oxidation catalyst intimately bonded to said crown, insulating means as part of said crown to reduce heat loss through said crown, said catalyst having a surface sufficiently nonporous so as to be substantially non-wettable by fuel at engine operating conditions whereby said catalyst is effective for ignition of said fuel when said catalyst is hot. 
     
     
       2. The piston of claim 1 wherein said insulating means comprises a ceramic. 
     
     
       3. The piston of claim 2 wherein said ceramic comprises stabilized zirconia or stabilized hafnia. 
     
     
       4. The piston of claim 1 wherein said insulating means comprises a thermal break underlying and spaced from said catalyst. 
     
     
       5. The piston of claim 1 wherein said catalyst comprises platinum or a base metal oxide or a perovskite. 
     
     
       6. The piston of claim 1 wherein said catalyst is applied as a patterned coating. 
     
     
       7. The piston of claim 1 wherein said crown comprises silicon nitride. 
     
     
       8. The piston of claim 1 including an air cell in said crown. 
     
     
       9. The piston of claim 8 including means for cooling said air cell. 
     
     
       10. The piston for use in compression ignition engines having a crown, said crown having an intimately bonded oxidation catalyst comprising a noble metal or a base metal oxide, said catalyst being thermally insulated to control heat loss through said crown, said catalyst being applied in a patterned coating to an insulation comprising a stabilized zirconia or a stabilized hafnia and being sufficiently nonporous so as to be non-wettable by fuel at engine operating conditions whereby said catalyst is effective for ignition of said fuel when said catalyst is hot. 
     
     
       11. A combination chamber for a catalytic ignition engine comprising: chamber walls, said walls comprising chamber sides, a chamber head and the crown of a piston means, an oxidation catalyst intimately bonded to at least a portion of the inner surface of said walls,   insulating means underlying said catalyst to reduce heat loss through said wall portion,   said catalyst having a surface sufficiently nonporous so as to be substantially non-wettable by fuel at engine operating conditions whereby said catalyst is effective for ignition of said fuel when said catalyst is hot.   
     
     
       12. The combustion chamber of claim 11 in which said insulating means comprises a ceramic. 
     
     
       13. The combustion chamber of claim 12 in which said ceramic comprises stabilized zirconia or stabilized hafnia. 
     
     
       14. The combustion chamber of claim 11 in which said insulating means comprises a thermal break underlying and spaced from said catalyst. 
     
     
       15. The combustion chamber of claim 11 wherein said catalyst comprises platinum or a base metal oxide or a perovskite. 
     
     
       16. The combustion chamber of claim 11 wherein said catalyst is applied as a patterned coating. 
     
     
       17. The combustion chamber of claim 11 including an auxiliary chamber and communicating therewith. 
     
     
       18. The combustion chamber for a catalytic ignition engine having walls comprising chamber sides, a chamber head and the crown of a piston means and comprising, insulation comprising stabilized zirconia or stabilized hafnia intimately bonded to at least a portion of said walls to reduce heat loss through said wall portion,   an oxidation catalyst comprising a novel metal or a base metal oxide,   said catalyst being applied in a patterned coating and intimately bonded to at least a portion of said insulation, the surface of said catalyst being sufficiently nonporous so as to be non-wettable by fuel at engine operating conditions whereby said catalyst is effective for ignition of said fuel when said catalyst is hot.